A sphere of influence is a list of people comprised of everyone you know and everyone who knows you. You encounter them everywhere you go, including work, school, in neighborhoods, through clubs and organizations, out shopping, doing errands, attending parties, and at a religious institution. Your sphere of influence is made up of the people with whom you interact throughout your life. It includes your family, close and distant friends, and people you know but with whom you are not well acquainted. If you work your sphere of influence aggressively, the people in it can help jump-start your career as they pass along information within their own spheres, sharing with their acquaintances and families that you can help them buy or sell real estate.

It is generally believed that the average adult knows about 400 people by name, and knows them well enough to have a conversation with them. This means that your immediate sphere includes about 400 people. If each person in your sphere of influence has a sphere of 400 people, the next sphere level contains 160,000 people! This means you have the chance of working with tens of thousands of people, not just the people in your sphere but also the people in their spheres.